Abstract
An EPR experiment is studied where each particle within the entangled pair undergoes a few weak measurements (WMs) along some pre-set spin orientations, with the outcomes individually recorded. Then the particle undergoes one strong measurement along an orientation chosen at the last moment. Bell-inequality violation is expected between the two final measurements within each EPR pair. At the same time, statistical agreement is expected between these strong measurements and the earlier weak ones performed on that pair. A contradiction seemingly ensues: (i) Bell’s theorem forbids spin values to exist prior to the choice of the orientation measured; (ii) A weak measurement is not supposed to determine the outcome of a successive strong one; and indeed (iii) Almost no disentanglement is inflicted by the WMs; and yet (iv) The outcomes of weak measurements statistically agree with those of the strong ones, suggesting the existence of pre-determined values, in contradiction with (i). Although the conflict can be solved by mere mitigation of the above restrictions, the most reasonable resolution seems to be that of the Two-State-Vector Formalism (TSVF), namely, that the choice of the experimenter has been encrypted within the weak measurement’s outcomes, even before the experimenters themselves know what their choice will be.
Highlights
Bell's theorem [1] has dealt the final blow on all attempts to explain the EPR correlations [2] by invoking previously existing local hidden variables
While the EPR spin outcomes depend on the particular combination of spin-orientations chosen for each pair of measurements, Bell proved that the correlations between them are cosine-like and nonlinear Eq (1) these combinations cannot all co-exist in advance
Such a past-to-future effect can be straightforwardly ruled out by posing the following question: How robust is the alleged bias introduced by the weak measurements? If it is robust enough to oblige the strong measurements, it is equivalent to full collapse, namely local hidden variables, already ruled out by Bell's inequality
Summary
Bell's theorem [1] has dealt the final blow on all attempts to explain the EPR correlations [2] by invoking previously existing local hidden variables. Nonlocal effects between the two particles have been commonly accepted as the only remaining explanation It is possible, to explain the results without appeal to nonlocality, by allowing hidden variables to operate according to the Two-State Vector Formalism (TSVF). As this proof is bound to elicit attempts to find loopholes within it, we describe it elsewhere in greater detail and with several control experiments [3]. 4 describes a combination of strong and weak measurements on a single particle illustrating a prediction of TSVF. Consider a large ensemble of N particles, each undergoing two consecutive strong measurements, along the co-planar spin orientations α and β The correlation between their outcomes depends on their relative angle θαβ:. The probability seems to have a definite value which agrees with both outcomes, due to two state-vectors [5], one evolving from the past, t
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
